Electric circuit breaker



. L. J. LINDE ELECTRIC CIRCUIT BREAKER Feb. 27, 1940.

Filed June 13. 1939 Inventor: Leonard J. Linda Hrs Attobneg Patented Feb. 27, 1940 I PATENT OFFICE 2,192,045 ELECTRIC omcurr BREAKER.

Leonard J. Linde, Drexel Hill, Pa., assignor to General Electric Company, a. corporatiom ol.

New York Application June 13, 1939, Serial No. 278,855

4 Claims.

My invention relates to electric circuit breakers, and more particularly to circuit breakers of the type wherein an arc-extinguishing gas is emitted by an arc-confining structure under the 5 influence of the are heat.

In breakers of this type it is desirable to provide for a large contact area between the arc and the walls of the arc-confining passage so that arc-extinguishing gas will be liberated in sufii- 10 cient quantities to create a pressure that will extinguish the arc effectively, and it is an object of this invention to provide an improved circuit breaker construction which provides for an extended contact area between the arc and the gasemitting material and results in a circuit breaker having a high current interrupting capacity for its physical size. I

It is another object of this invention to provide an improved circuit breaker construction 20 which is structurally strong, reliable in service and economical to manufacture.

Further objects and advantages of the invention will become apparent as the following description proceeds, reference being had to the 25 drawing in which Fig. l is anelevational view in section of a circuit breaker embodying the invention, and Fig. 2 is a sectional view taken along the lines 2--2 of Fig. 1.

The circuit breaker illustrated in the drawing,

' 30 by way of example, comprises an arc-confining structure designated generally by the numeral I0, a stationary contact I l and a movable contact rod l2. The arc-confining structure illustrated is in the form of an elongated body of insulating mate- 35 rial made up of a plurality of disks l3 which are assembled in a cylindricalhousing I4 of insulating materiaL- The disks may be stacked and secured together by suitable fastening means extending longitudinally therethrough, in which case the housing may be omitted if desired. At one end the structure is closed by a housing 15 of conducting material which may be secured to one end of the insulating cylinder I4 by any suitable means (not shown). Between the conduct- 45 ing housing and the upper disk b f\the arc-confining structure is positioned the stationary contact H which may be in the form of an annular segmental ring, in which the'segments are resiliently bound together by an encircling helical 50 spring l6. s

The arc-confining structure is provided with an arc-confining passage l1 extending longitudinally therethrough for the reception of the mov- 'able contact rod. The passage I1 is of such vm5 curvilinear cross-section that a rib or pencil l8 which are stacked and secured together in any suitable manner with the slots in alignment to provide the arc-confining passage. This structure is very easy to manufacture since the disks may be formed in the desired shape without any 10 difiiculty.

The hollow movable contact is provided with a longitudinal slot IQ of such width as to accommodate the rib i8 at the region where the rib connects with the body of the arc-confining structure. With the construction just described, it is apparent that the rib I8 is partially surrounded by the movable contact so that there is an extended area of contact between the walls of the arc-confining passage and movable contact. The rib or pencil 18 which lies within the movable contact is supported throughout its length from the side wall of the arc-confining passage and in the particular embodiment illustrated forms an integral part of the remainder of the arc-confining structure.

The insulating material which forms the arcconfining structure is of the type which emits arc-extinguishing gas under the influence of the are heat and may be, for example, a suitable artificial resin or a hard fiber having this characteristic. It is not necessary that the entire structure be of gas-emitting material since it is possible to provide the arc-confining passage with a lining of material having this characteristic.

When heavy current arcs are drawn in the arc passage large quantities of gas are emitted from the walls thereof under the influence of the arc and. in order to avoid excessive pressure within the arc passage in the illustrated embodiment suitable radial vents 20 are provided intermediate the ends of the. arc passage. These vents may communicate with a mufiier and expansion chamber (not shown) mounted concentrically with the arc-confining structure. 'Such a constructiorris shown and described in Patent No. 2,152,497, Petermichl, dated March 28, 1939.

. In the operation of the circuit breaker above described the movable contact rod is moved downwardly from the position shown in Fig. 1 by a suitable operating mechanism (not shown) in response to a circuit condition to be controlled. Upon separation of the fixed and movable contacts an arc is drawn in the passage H which acts upon the gas-emitting material defining the passage to liberate quantities of arc-extinguishing gas. As the rod I2 is withdrawn from the passage the vents 20 are opened and in the case of a heavy current are such as exists under short circuit conditions suflicient gas will have been liberated to extinguish the are at this point and the hot ionized gases are exhausted through the radial vents. If the arc is not extinguished at this point, the action of the are on the gas-emitting material continues as the movable contact is withdrawn until the arc is extinguished before the movable contact reaches its lower limit of travel.

From the foregoing description it is seen that the invention provides a novel circuit breaker construction in which an extended area of contact is provided between the walls of an arc passage defined by material having gas-emitting properties under the influence of an electric arc. The improved structure provides for supporting the portion of the insulating material which lies within the movable contact from a sidewall of the arc passage thereby eliminating additional supporting means and, at the same time, providing a structure which is easier to manufacture and more durable in use.

While I have shown and described a particular embodiment of my invention, modifications thereof will be apparent to those skilled in the art. I do not therefore desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications within the spirit and scop of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric circuit breaker comprising means for forming an elongated arc-confining passage, said passage being defined by insulating material adapted to emit an arc-extinguishing gas under the influence of an electric arc, a rib of insulating material extending longitudinally of said passage and supported from a side wall thereof, relatively movable contacts separable to form an arc in said passage, one of said contacts having such cross-sectional configuration as to enclose partially said longitudinally extending rib.

2. An electric circuit breaker comprising a body of insulating material having an elongated arcconfining passage formed therein, a fixed conable contact having a curvilinearcross-section.

such as to enclose partially said rib.

3. An electric circuit breaker comprising a body of insulating material having an arc-confining passage formed therein, a fixed contact, a movable contact separable from said fixed contact to form an arc in said passage, said passage being defined by insulating material adapted to emit an arc-extinguishing gas under the influence of are heat, said body of insulating material having an integral portion extending into said passage and longitudinally thereof, said movable contact having such a cross-sectional configuration as to enclose said integral portion extending into said passage in the closed circuit position of said circuit breaker.

4. An electric circuit breaker comprising means forming an elongated arc-confining passage, a fixed contact, a hollow movable contact separable from said fixed contact to form an arc in said passage, said passage being defined by insulating material adapted to emit an arc-extinguishing gas under the influence of the are heat, and a rib of insulating material formed integrally with a side Wall of said arc-confining passage and extending longitudinally thereof, said movable contact having an elongated slot therein for receiving said rib in the region of connection with the side wall whereby said rib lies within said hollow movable contact when the circuit breaker is in its closed position.

LEONARD J. LINDE. 

